CONFIG_CONSOLE_VGA will redirect console messages to the VGA screen once VGA card is initialized.

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to the VGA screen once VGA card is initialized.

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For addon VGA cards, you don't have to do anyting else besides these two CONFIG options.

For addon VGA cards, you don't have to do anyting else besides these two CONFIG options.

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VGA card will be used instead of the onboard VGA chip.

VGA card will be used instead of the onboard VGA chip.

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If you want to use the onboard VGA chip, you have to do the following in additional

+

If you want to use the onboard VGA chip, you have to add the following options in addition to the CONFIG options described above.

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to the CONFIG options described above.

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−

1. in MB Config.lb You need to specify for your onboard VGA

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1. In the mainboard Config.lb (.src/mainboard/<mfg>/<board>/Config.lb) You need to specify for your onboard VGA

device pci 9.0 on # PCI

device pci 9.0 on # PCI

chip drivers/pci/onboard

chip drivers/pci/onboard

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end

end

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Please make sure the device num should be right. Otherwise it can not

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Please make sure the device number is correct. Otherwise it the config code can not compute the proper ROM address.

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get exact ROM address.

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−

+

−

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2. You still need to modify your target Config.lb.

2. You still need to modify your target Config.lb.

Revision as of 23:23, 23 April 2006

There are two kinds of VGA devices

1. onboard vga
2. addon card.

You need to enable two CONFIG options in your Mainboard Option.lb

#VGA Console
option CONFIG_CONSOLE_VGA=1
option CONFIG_PCI_ROM_RUN=1

CONFIG_PCI_ROM_RUN will use the embedded x86 emulator to run the BIOS image in the expansion ROM of a PCI device.
CONFIG_CONSOLE_VGA will redirect console messages to the VGA screen once VGA card is initialized.

For addon VGA cards, you don't have to do anyting else besides these two CONFIG options.
If your mainboard has an onboard VGA chip and you insert another VGA addon card, the addon
VGA card will be used instead of the onboard VGA chip.

If you want to use the onboard VGA chip, you have to add the following options in addition to the CONFIG options described above.

1. In the mainboard Config.lb (.src/mainboard/<mfg>/<board>/Config.lb) You need to specify for your onboard VGA

How to retrieve a good video bios

There are sites that have video bios roms on their website. (I know of this one for nvidia cards: [1])

However you should be able to retrieve your own video bios as well with linux.

Boot up a machine with a commercial bios (not linux bios) with the video card you wish to work under linux bios.

From the command line enter:dd if=/dev/mem of=vgabios.bin skip=1536 count=128 or dd if=/dev/mem of=vgabios.bin bs=1k count=64 skip=768This assumes you card's bios is cached at 0xc0000, and is 64K long. Youcan see where and how much your card's bios is using bydoing a cat iomem | grep "Video ROM"

dd Explained (man dd to learn more):

if is the location to retrieve from.

of is the output file (your rom image)

skip jumps n blocks where the default n is 512 bytes

count is how many blocks you wish to read

bs is the block size

You now have a video bios image

Perl script to dump out your video bios

This is a simple script that computes the size and offset then uses
the command dd to dump your video bios to a file.